Granular materials including ores, plastics and metallic materials are commonly treated by a variety of separation devices to concentrate or upgrade one or more of the constituents. Magnetic separators and electrostatic separators are well known and available to perform some of these tasks. Usually such separators function with a moving surface to receive and transport the mixture of particles under a magnetic or electrostatic field to perform the separation. The introduction of materials to various separation devices plays an extremely important role in the quality and efficiency of the separation which is to take place. Proper introduction of materials and/or feeding to any separation device will also reduce wear of separator components due to particle bounce and scattering thereof. It is therefore necessary, if the separation is to be as efficient as possible, that the mixture of particles be (1) distributed uniformly and thinly across the moving surface, and (2) be introduced at approximately the same speed or trajectory across the surface. The moving surface may be an endless belt, a revolving cylinder, a rotating conical surface or the like.
It is an object of this invention to provide a device for feeding particulate material in an even distribution across the width of a moving surface, especially for purposes of separating the particles into individual types. It is another object of this invention to provide a feeding mechanism for subsequent electrostatic or magnetic separation of different types of particles. Still other objects will be apparent from the more detailed description of this invention which follows.